A week ago we found one of our bulls had taken himself off away from his group of cows and calves. He was lying down depressed and slightly dehydrated. He has not lost his appetite and is now drinking well. He has lost condition though. We dosed him with penicillin and he has improved over the last couple of days but still has not re-joined his group. He has one runny eye and a runny nose today but his appetite is good and he is getting extra rations. What could be wrong with him? We are worried it is IBR. Any help and advice would be gratefully received.